Single bath chromic chloride mineral dyeing process for cellulosics

ABSTRACT

CONVENTIONAL &#34;PEARL GRAY&#34; CHROME GREEN MINERAL DYEINGS REQUIRE A DOUBLE DEOMPOSITION PROCCESS FOR DEPOSITING GREEN CHROMIUM OXIDE IN CELLULOSICS. BY FORMING A UNIQUE ALKALINE COMPLEX OF A CHROMIC CHLORIDE WITH AMMONIUM OXALATE AND ZIRCONYL AMMONIUM CARBONATE, A SINGLE DYE BATH IS PRODUCED, ENABLING THE DYES TO APPLY THE 2PEARL GRAY&#34; CHROME GREEN MINERAL DYEING BY A SIMPLE PAD DRY, CURE, AND WASH PROCEDURE. THE DYEINGS ARE UNIFORM AND THE CELLULOSIC IS NOT TENDERED OR PHYSICALLY DEGRADED. NOT ONLY DOES THIS INVENTION REDUCE PROCESSING STEPS, BUT IT ELIMINATES THE CONVENTIONAL PROBLEM OF TENDERING RESULTING FROM DRYING THE CHROMIC CHLORIDE ON CELLULOSICS PRIOR TO PROCESSING THROUGH A SECOND BATH OF SODA ASH AND SOAP. THE INVENTION MAKES IT POSSIBLE TO PREPARE A MODIFIED CHROMIC CHLORIDE STOCK SOLUTION THAT CAN BE USED FOR EITHER THE CONVENTIONAL &#34;PEARL GRAY&#34; PROCESSING OR THE SINGLE BATH PROCESS DESCRIBED ABOVE.

United States Patent 3,794,466 SINGLE BATH CHROMIC CHLORIDE MINERAL DYEING PROCESS FOR CELLULOSICS Charles J. Conner, Metairie, La., assignor to the United States of America as represented by the Secretary of Agriculture No Drawing. Original application Aug. 31, 1971, Ser. No. 176,736. Divided and this application Apr. 27, 1972, Ser. No. 248,247

Int. C1. C09]: 61/00; D06p 3/60 U.S. Cl. 8-52 3 Claims ABSTRACT OF THE DISCLOSURE Conventional pearl gray chrome green mineral dyeings require a double decomposition process for depositing green chromium oxide in cellulosics. By forming a unique alkaline complex of a chromic chloride with ammonium oxalate and zirconyl ammonium carbonate, a single dye bath is produced, enabling the dyes to apply the pearl gray chrome green mineral dyeing by a simple pad, dry, cure, and Wash procedure. The dyeings are uniform and the cellulosic is not tendered or physically degraded. Not only does this invention reduce processing steps, but it eliminates the conventional problem of tendering resulting from drying the chromic chloride on cellulosics prior to processing through a second bath of soda ash and soap. The invention makes it possible to prepare a modified chromic chloride stock solution that can be used for either the conventional pearl gray processing or the single bath process described above.

This is a division of application Ser. No. 176,736, filed Aug. 31, 1971.

A non-exclusive, irrevocable, royalty-free license in the invention herein described, throughout the world for all purposes of the United States Government, with the power to grant sublicenses for such purposes, is hereby granted to the Government of the United States of America.

It has been known from prior art that chromic chloride reacts with alkali hydroxides and carbonates to produce grayish-green color, and referred to in mineral dyeing a precipitate of hydrated chromium oxide, having a terminology as pearl gray. When a cellulosic is wetted with chromic chloride, dried, and then wetted with an alkali hydroxide or carbonate solution, this precipitated hydrated chromium oxide is deposited in the cellulosic to attribute a gray-green color (mineral dyeing). The prior art teaches that this wet dyed cellulosic must then be washed, treated with fungicide and then dried.

The present invention consists of treating the chromic chloride with ammonium oxalate and an ammoniacal solution, which produces an alkaline aqueous soluble complex of hydrated chromium oxide with ammonium oxalate. When Zirconyl ammonium carbonate is used with ammonium hydroxide, a water soluble chromium zirconium hydrated oxide complex is produced with the excess ammoniacal alkalinity. When this solution (bath) is applied to cellulosics, and the cellulosics heated to dryness and cured at temperatures of 130 C. to 150 C., the hydrated zirconia and green chromium oxide are deposited as an insoluble residue to produce a uniform mineral dyeing. When copper metaborate, copper hy- 3,794,466 Patented Feb. 26, 1974 droxide, or copper carbonate is solubilized in the ammonium hydroxide, prior to addition to the formulation, the bath is compatible, and a fungicidal pearl gray mineral dyeing is deposited in cellulosics by heat curing.

The main object of the invention is to provide a singlebath chrome mineral dye bath from conventional chromic chloride to eliminate double decomposition baths and produce uniform pearl-gray mineral dyeings by a simple pad, dry, and cure procedure, followed by wash and dry to remove byproducts.

A second object of the invention is to provide a single modified chromic chloride stock solution, which can be used for single bath or conventional pearl-gray mineral dyeing.

A third object of the invention is to provide a single dye bath from chromic chloride and copper compounds, to produce fungicidal pearl-gray mineral dyeings by a simple pad, dry, and cure procedure.

A fourth object of the invention is to provide a single bath from chromic chloride, copper compounds, and paraffin-ammonium stearate emulsion components to deposit a fungicidal pearl-gray mineral dyeing with water repellent finish, by a simple pad, dry, cure procedure.

The prior art teaches that chromic chloride will degrade and tender cellulosics when heat dried on them. This invention enables the use of chromic chloride in ammoniacal zirconium complex without tendering or degrading the cellulosic. The prior art also teaches that conventional pearl-gray mineral dyeing requires a double decomposition procedure, followed by a treatment with fungicide. The present invention applies the mineral dyeing and fungicide from the same single bath system. The prior art teaches that conventional water repellent finishes are applied last to the dye and fungicide treated cellulosic. The present invention incorporates the wax finish in with the dye and fungicide, in a single bath, to produce fungicidal mineral dyeings with water repellent finish by a simple pad, dry, and cure procedure.

Utility of the invention is obviously in the field of mineral dyeings and weatherable goods, such as for tents, sails, tarpaulins, umbrellas, awnings, rope, shoe lining, rainwear, boat covers, canvas shoes, upholstery, etc.

A preferred process for dyeing cellulosic textiles pearlgray chrome green in a single bath comprises: (a) wetting the cellulosic material With an activated, water-based composition of matter consisting of chromium chloride in an amount sufiicient to provide from about 2.5 to 3.2 weight percent of chromium, about 5.0 weight percent of ammonium oxalate monohydrate, zirconyl ammonium carbonate in an amount sufiicient to provide about 2.5 weight percent of zirconium dioxide and ammonium hydroxide in an amount sufiicient to provide about 2.0 weight percent of ammonia, (b) oven drying the wetted material from step (a) at about a temperature of from C. to C. for a period of from 2 to 4 minutes, (c) oven-curing the dried material from step (b) at about a temperature of from C. to C. for a period of from 2 to 4 minutes, (d) water washing the cured material from step (c) for a period of from 1 to 2 minutes and (e) oven-drying the washed material from step (d) at a temperature of from 110 C. to 120 C. for a period of from 2 to 4 minutes.

The following examples are presented to illustrate the invention and certain aspects of its usefulness. These are not to be interpreted as limiting the invention in anymanner whatever. The treatments were also applied to paper, porous ceramics, wood, and other fabrics having cellulosic compositions.

EXAMPLE 1 Four stock solutions of chromic chloride, having chromium metal contents of 8%, and 16% were formulated into the following formula:

Grams Chromic chloride stock (8%-10% Cr) 25.00 Water (distilled) 25.00 Ammonium oxalate crystals (fine) 4.00 Zirconyl ammonium carbonate (10% ZrO 20.00 Ammonium hydroxide (29.4% NH 5.00

Single bath 79.00

The 8% and 10% chromic chloride stock solutions were compatible while the 15% and 16% stock solutions produced gelatinous gray-green precipitates, and were incompatible. The chromic chloride chromium content is a limiting factor, and cannot exceed 10%, being desirable at 8% chromium.

EXAMPLE 2 The following formulation was satisfactory for chromic chloride stock solutions having chromium contents of percentage values from 10% to 16%:

Grams Chromic chloride stock (10%-16% Cr) 15.0 Distilled water 35.0 Ammonium oxalate crystals (fine) 4.0

Zirconyl ammonium carbonate (10% ZrO 20.0 Ammonium hydroxide (29.4% NH 5.0

Single bath 79.0

The ammonium oxalate was completely dissolved in the chromic chloride and Water. Zirconyl ammonium carbonate was added without stirring, then the ammonium hydroxide immediately. The mix is then agitated rapidly until a clear blackish-green bath results.

EXAMPLE 3 The following formulation represents a single bath system with an 8% Cr chromic chloride stock and copper metaborate to produce a fungicida pearl-gray mineral dyeing:

EXAMPLE 4 The bath from Example 1 (with 8% chromic chloride stock formulation) was used to wet several pieces of 4" x 8" scoured 9 oz. army duck. The wetted duck was blotted and oven dried at 110 C. to 120 C. for 2 to 4 minutes, followed by oven-curing at 130 C. to 140 C. for 2 to 3 minutes. The cured fabric was dyed a deep gray-green mineral dyeing (pearl gray). The cured samples were washed in both hot and cold running tap water and oven dried at 110 C.-120 C. for 2 to 4 minutes. The fabrics remained a deep gray-green dyed color shade, and were stable to water washings.

EXAMPLE 5 The bath from Example 3 was similarly applied to samples of 9 oz. army scoured duck, using the procedures of Example 4. The duck was dyed a deep grayish-green 4 (pearl gray) mineral dyeing, having a copper (fungicidal) content of 0.5% Cu.

EXAMPLE 6 Preparation of modified chromic chloride, which can be used for single bath application per Examples 1 through 5, or for conventional pearl gray mineral dyeings:

Grams chromic chloride stock (8%-l0% Cr) 25.00 Distilled water 25.00 Ammonium oxalate crystals (fine) 4.00

Modified stock chromic chloride 54.00

EXAMPLE 7 The use of Example 6 is demonstrated for both conventional and single bath mineral dyeing, as follows:

(a) Conventional Dyeing: A 4" x 5" sample of scoured duck was wetted with the bath formulation (54 grams) of Example 6, and oven dried at C. to C. for 2 minutes (approximately 8% to 10% retained moisture in the dried and treated fabric). This dried fabric was then wetted thoroughly with a 10% sodium carbonate solution, to produce a mineral dyeing of hydrated chromium oxide in the fabric (mineral dyed). The wet dyed fabric was then oven dry-cured at C.- C. for 3 to 4 minutes, followed by a l to 2 minute tap water rinse and oven drying at 120 C.130 C. for 2 minutes. The fabric was mineral dyed a gray-green color. The addition of 1% to 2% soft soap (potassium stearate or comparable) to the soda ash bath assures better lock-on and a greener shade of color.

(b) Single Bath Dyeing: A 4" x 6" sample of scoured duck was treated With the further modification of the Example 6 stock:

Grams Modified chromic chloride (Example 6) 54.0 Zirconyl ammonium carbonate (10% ZrO 20.00 Ammonium hydroxide (29.4% NH 5.00

Single bath (pearl gray) 79.00

The drying and curing procedure were the same as in Example 4. A deep gray-green mineral dyeing resulted.

EXAMPLE 8 A sample of the scoured duck treated in Example 3 (with copper metaborate-chromic chloride complies with zirconium) was soil buried for one week with a piece of untreated scoured duck (control). After 4 weeks, the control fabric had rotted out, while the treated fabric retained 20% strength.

EXAMPLE 9 Samples from the single bath treatments in Examples 4, 5, and 7 (conventional) were exposed on the weather rack for 6 months along with untreated scoured duck. No growths were evidenced on the treated samples, while some algae and mildew growths were noted on the control sample.

The washed fungicidally dyed fabrics produced according to Examples 4 and 5 can be wax finished by conventional paddings through a 7% to 9% paraflin (paraffin-ammonium stearate emulsion) to obtain 3% to 4% paraffin add-ons, followed by oven dry at 110 to 120 C. for 2 minutes and oven curing at C. to

150 C. to melt the paraffin into the fabric and decompose the ammonium stearate. The NH leaves the fabric as gas, and the stearic acid combines with the zirconia to produce zirconium stearate.

The aqueous 7 to 9 weight percent paraffin ammonium stearate emulsion can be conveniently prepared by diluting, with effective stirring, 2000 grams of a commercially available paraffin-ammonium stearate wax emulsion paste with 8000 grams of water. This will produce 10,000 grams of a paraffin wax pad bath containing about 7 weight percent of parafiin wax.

EXAMPLE 10 The washed-dyed fabrics from Examples 4 and 5 were Wetted with an 8% paraffin-paraflin ammonium stearate emulsion, blotted free of excess liquid, and oven dried for 2 minutes at 120 C. The dried fabric was then cured at 145 C.150 C. for 2 minutes, and allowed to condition at room temperature (250 C.) for one hour. The treated fabric was completely water repellent, spray rating 90 to 100. This example was repeated in the pilot plant in four runs, where the emulsion was applied by conventional padding, and drying and curing effected in a continuous oventender frame operation, using 110 C. for 2 minutes in drying, and 150 C. for two minutes in curing. The same excellent water repellency resulted.

I claim:

1. An unactivated, water-based composition of matter useful as a storable stock solution to effect, when activated, pearl gray chrome green mineral dyeing, which composition consists of chromium chloride in an amount sufficient to provide about from 2.5 to about 3.2 weight percent of chromium and about 5.0 weight percent of ammonium oxalate monohydrate.

2. An activated, water-based composition of matter useful to effect pearl gray chrome green mineral dyeing consisting of chromium chloride in an amount sufficient to provide about from 2.5 to about 3.2 weight percent of chromium, about 5.0 Weight percent of ammonium oxalate monohydrate, zirconyl ammonium carbonate in an amount sufficient to provide about 2.5 weight percent of zirconium dioxide and ammonium hydroxide in an amount sufficient to provide about 2.0 weight percent of ammonia. 3. A process for dyeing cellulosic textiles pearl gray chrome green in a single bath which process comprises: (a) wetting the cellulosic material with the water based composition of claim 2, (b) oven-drying the wetted material from step (a) at about a temperature of from C. to C. for a period of from 2 to 4 minutes,

(0) oven-curing the dried material from step (b) at about a temperature of from C. to C. for a period of from 2 to 4 minutes,

(d) water washing the cured material from step (c) for a period of from 1 to 2 minutes,

(e) oven-drying the washed material from step (d) at a temperature of from 110 C. to 120 C. for a period of from 2 to 4 minutes.

References Cited UNITED STATES PATENTS 2,035,527 7/1932 Brown 8-95 X 3,431,059 3/1969 Conner et a1. 8--52 DONALD LEVY, Primary Examiner B. H. HESS, Assistant Examiner US. Cl. X.R. 8-l7 

